Granular Cell Tumor

Key Points
Usually benign skin tumor
Exact cause is unknown
Consists of small nodule, usually painless, though it may be accompanied by mild itching or tenderness

Granular cell tumors are skin tumors which originate in schwann cells, and are almost exclusively benign, though rare instances of malignancy have been reported. The tumor consists of a single small nodule which shows no color variation. The lesion surface may be smooth or only slightly rough, and are usually painless, though it may be accompanied by mild itching or tenderness. Lesions most often occur on the head and neck, or tongue, though they may occur anywhere on the body, and even internal organs in rare cases. Some persons may experience multiple lesions in association with other conditions. The formation of multiple lesions may also run in families.

The exact cause of granular cell tumors is unknown. They may affect all age, gender and ethnic groups, though they appear more commonly in women. They usually appear in middle life, between 30 and 50 years. While most are idiopathic (forming without an associated condition), these tumors, especially when occurring in multiples, may form in association with other conditions, and in this situation may also be hereditary.

Differential Diagnosis (Other conditions with similar appearance)
Basal cell carcinoma
Leiomyoma
Angiosarcoma
Schwannoma
Leiomyosarcoma
Dermatofibroma

Diagnosis
Key Points
Initial diagnosis based on lesion appearance
Skin biopsy will be performed to confirm diagnosis and rule out other, similar-appearing conditions

The initial diagnosis of a granular cell tumor is based on the appearance of the lesion. A clinical examination of patient history in conjunction with a biopsy of the lesion will be performed to confirm the diagnosis and rule out other, similar-appearing conditions.

Treatment
Excision is the primary form of treatment
*While 98% of tumors are benign, in cases where malignancy is detected, further treatment may be needed

Excision is the primary form of treatment for granular cell tumors. Often this excision will also assist diagnosis. While the majority of granular cell tumors appear singly, in some cases multiple lesions may form. These cases are often due to an underlying condition, which may require further testing and treatment. Additionally, in rare cases the tumor may be malignant, and require further and more aggressive forms of treatment.